Question

1. Mark an O on the picture you like, and mark an X on the picture you don't like.

2. Mark O on the picture you like, and mark X on the picture you don't like.

3. Check a circle on the picture you like, and check an X on the picture you don't like.

4. Check circle on the picture you like, and check X on the picture you don't like.

(Which sentences are grammatical? are all grammatical?)

Answer 1

1 and 2 are fine. 3 and 4 don't make sense.